Mechanism for driving sieves.



K. ROJAHN.

MECHANISM ron DRIVING slnvss.

APPLICATION IILBD DEU. 31, 1912.

1,1 1 6,124. Patented Nov. 3, 1914.

Mfg@

UNITED STATES NPATENT oEEioE- KARL BOJAHN, 0F BRUNSWICK, GERMANY, ASSIGHOR T0 AIME, GIESECKE & KONEGEN,

AKTIENGESELLSCHAFT, 0F BRUNSWICK, GERMANY, A. CORPORATION 0F GEB- MANY.

MECBANISM FOR DRIVING SIEVEB.

- Specification of Letters Patent. Application led December 31, 1912. Serial No. 739,526.

Patented Nov. 3, 1914.

of a revolving body mounted on the sieve and adapted by centrifugal action to impart to the Asieve parallel swinging movement along a circular-path.

The object of the improvements is to provide a driving mechanism which is simple in construction and effective in operation.

With this object in view my invention consistsof thematters to be described hereinafter and particularly pointed out in the appended claims, reference being had to the accompanyinv drawing and the letters of reference marked thereon, which form a part of this specification.

In said drawing-Figure 1, is a diagrammatical side view of a sieve, its sup citing means and drivin member illustrating the principle on whic the invention is based, Fig. 2, is a diagrammatical plan showing the revolving driving member and the center of revolution of the system, Fi 3, is a side view partly insection illustrating in a dia- -grammatical'way an embodiment .of the invention, and Fig. 4, is a side view partly in section showing a modification of .a detail.

The same-letters of reference have been used in all the views to indicate correspondin parts.

n order that my invention be more clearly understood, I deem it best first to describe the general principle on which it is based.

Referring to the diagrammatical' views shown inFi s. 1 and 2, a plane sieve a is mounted in t e usual way on four links or elastic rods b, and carries on a vertical axis or shaft c and at the end of an arm s a revolving body m.- If the body m, is made to revolve, the reaction causes the sieve to move ,along a circular path which in Fig. 1 has been indicated by the letter k, and each point of the sieve moves along a similar circular path. Therefore, while-the body m revolves around the axis valso the axis c revolves in` thesame sense in a circular path, as has been indicated 1n Fig. 2 by the arrow d. Therefore, as the ends'of the arm s perform revolving' movements along circular paths, it follows, that there is a point p of the said arm which is relatively stationar andy constitutes the axis of revolution o the arm. If

a vertical shaft w is rigidlyconnected with the arm s at the point p, as is shown in Fig. 3, and the said shaft is' rotated by means of a belt gearing or the like, lthe shaft does noty change its position while the sieve a moves alon a regular or normal circularpath and the ody m revolves, and it rotates around its longitudinal axis. Hence a shaft arran ed in this manner may be used without having to ybe mounted in fixed sleeve-bearings, as is the case with the crank-drive emplo ed in the plane sieve shown in Fig. 1.

Since the shaft w has a tendency, in ex ceptional cases, e. g. in changeof load of the plane sieve and shiftin of its center of rotation p, to make smal turns, said shaft is somounted as to enable it to follow this tendency by being yieldingly suspended at its upper end for movement in all directions. The suspension mounting consists as shown in Fig. 3 of a ball e and socket f. Wherethe shaft w is driven by means of a belt eating, the pulley o can be rigidly secure to the shaft, as is shown in Fig. 3, or 1t ina have a stationary support, as is shown in i 4, in which case it is connected with the s aft w by means of a universal joint e1.

Preferably the construction of the system is such, that the bearing of the shaft c, the center of gravitation of the sieve andthe center of' gravitation of the body m are so located, that the horizontal forces are within the same horizontal plane, so that they balance one another, and a' momentum is avoided. Also the said shaft or pivot c is so mounted as to be capable of such freedom of movement as not to bind when the shaft w and, consequently, .the arm s are inclined.

My improved construction of the driving mechanism possesses the following advantages: As the body m is eccentricallymounted on the shaft fw, and the latter is pivotally suspended from its socket f, it presses the sieve .also inthe position of rest into the osition which corresponds to the radius of its circle of revolution, as is shown in Fig. 3, so that it. is not necessaryto gradually move the sieve in this position vwhen starting the operation, as is necessary with the` arrangement shown m Fig. l. lin the construction shown in 3 the body m doesnot hear on the sieve, but it is supported on the shaft w. Therefore, vvhenthe body m is revolving the tensional strain -on the npoints of support of the' rods b is not varied,

so that no ]ars are transmitted to the building in which the sieve iis provided. Furthermore no bearings are necessary for the shaft w which would likewise transmit shocks to the building. And finally objectional driving means for the body m suoli as flexible shafts, oscillating belts, etc., are avoided.`

l claim herein as my invention:

1. The combinatiomvvith a driven mein-r ber provided with a bearing, and supporting means for said member arranged to permit swinging movement along a closed curve; of

i a vertical drive shaft suspended at its upper onsaid member and. provided at its outer end with a Weight; a vertical drive shaft located above ,said-arm and havingits lower A for :tree oscillatory movement; and a lateral arm revolubly mounted at its inner end on said member and-rigidly attached to the lower end of said shait.l whereby the ends of said arm will move revoluhly through circular paths during the rotation of the shaft. the point at which said shaft and arm :we attached constituting the axis of revolution of the latter.

in testimony vvhereoi3 l have hereimto set my hand in presence of tvvo suoscrihin{ lr Witmesses.

KARL ROJAHN.

Witnesses Willmann Lamine, Heitmann lEAHLenne. 

